Retaining wall system

ABSTRACT

A retaining wall system for use in retaining a backfill particulate mass is formed by at least one retaining wall unit. The retaining wall unit has a substantially upright forward wall having a rear surface for abutting against the backfill particulate mass. A substantially upright stem wall extends rearward from the rear surface of the forward wall. The stem wall has opposite substantially upright sidewalls. At least one of the sidewalls has a series of longitudinally spaced apart elongated grooves that slope upward toward the forward wall.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying figures, in which:

FIG. 1 is a perspective view of a retaining wall unit for retaining wall system constructed in accordance with the invention;

FIG. 2 is a side elevational view of a retaining wall system employing stacked retaining wall units and constructed in accordance with the invention;

FIG. 3 is a perspective view of stacked retaining wall units exploded apart to show a cooperating tooth and notch of the stacked retaining wall units;

FIG. 4 is a transverse cross-sectional view of a stem wall of the retaining wall unit of FIG. 1, taken along the lines 4-4;

FIG. 5 is a transverse cross-sectional view of an alternate embodiment of a stem wall of a retaining wall unit;

FIG. 6 is a side elevational view of a retaining wall unit showing a longitudinal cross section of a stem wall of the unit illustrating a reinforcement bar configuration of the stem wall;

FIG. 7 is a side elevational view of a retaining wall system retaining a mass of back fill material and illustrating a failure plane of the back fill material;

FIG. 8 is a front elevational view of a retaining wall system employing cap units;

FIG. 9 is a rear perspective view of a cap unit for use with the retaining wall system of FIG. 8;

FIG. 10 is a top plan view of a retaining wall system employing face wall units;

FIG. 11 is a front elevational view of a face wall unit of FIG. 10;

FIG. 12 is a top plan view of an alternate embodiment of a face wall unit having a recessed rearward face;

FIG. 13A is a lower level corner assembly of a corner retaining wall system; and

FIG. 13B is an upper level corner assembly that may be stacked on top of the corner assembly of FIG. 13A to form the corner retaining wall system.

DETAILED DESCRIPTION

Referring to FIG. 1, a retaining wall unit 10 is shown for use in a retaining wall system, such as the retaining wall system 12 of FIG. 2. The retaining wall 10 and system 12 is of the type used to retain a backfill of a particulate or granular mass. The particulate mass may include earth or soil, sand, gravel, rock, etc., and combinations of these and other materials. In certain embodiments the particulate mass may initially be an unconsolidated particulate material but may be eventually consolidated and/or compacted. The backfill may be distributed in layers or “lifts” of selected depths (e.g. about 8 to 10 inches or less) and then compacted to a desired density. The retaining wall unit 10 and system 12 are used for retaining the particulate mass to prevent the advancement, collapse and/or erosion of the particulate material. The retaining wall systems described herein may be used with and located along roadways, railways, bridges, overpasses, drainage ditches and other embankments of various kinds.

The retaining wall system 12 of FIG. 2 is composed of several retaining wall units 10A, 10B, 10C that are stacked one on top of the other and that are constructed and configured similarly to the retaining wall unit 10 of FIG. 1 with similar components of the retaining wall units being labeled with the same reference numerals.

As shown, the retaining wall unit 10 of FIG. 1 includes a forward wall 14 that is oriented in a substantially upright or vertical orientation. The wall 14 may also be in an upright, but slightly sloped orientation (either rearward or forward), as well, provided it still retains its function of serving as a retaining wall, as described herein. In many embodiments, however, the wall 14 will be oriented vertically. The wall 14 has forward and rearward faces 16, 18, opposite left and right side edges 20, 22, and opposite top and bottom edges 24, 26. In the embodiment shown, the forward wall 14 is configured as a rectangular block wherein the forward and rearward faces 16, 18 are substantially flat and parallel to one another. The left and right side edges 20, 22 may be substantially flat and parallel to one another. The top and bottom edges 24, 26 may also be substantially flat and parallel to one another and are substantially perpendicular to the side edges 20, 22. While the wall 14 is shown and described as being configured as a substantially rectangular block, other configurations for the forward wall 14 may also be used provided the function and purpose of the wall, as described herein, is still retained.

The wall 14 may have different dimensions as well. As non-limiting examples, the wall may have a height of from about 2 to about 6 feet, a width of from about 4 to about 10 feet and a thickness of from about 4 to about 12 inches.

It should be noted in the description, if a numerical value or range is presented, each numerical value should be read once as modified by the term “about” (unless already expressly so modified), and then read again as not so modified unless otherwise indicated in context. Also, in the description, it should be understood that an amount range listed or described as being useful, suitable, or the like, is intended that any and every value within the range, including the end points, is to be considered as having been stated. For example, “a range of from 1 to 10” is to be read as indicating each and every possible number along the continuum between about 1 and about 10. Thus, even if specific points within the range, or even no point within the range, are explicitly identified or refer to, it is to be understood that the inventor appreciates and understands that any and all points within the range are to be considered to have been specified, and that inventor possesses the entire range and all points within the range.

Joined to the rearward face 18 of the forward wall 14 is a stem wall 28. The stem wall 28 projects rearward and is oriented in a substantially upright or vertical orientation. The stem wall 28 is oriented substantially perpendicular to the forward wall 14 and has substantially upright opposite sidewalls or faces 30 so that the retaining wall unit 10 has a substantially T-shape. The expression “upright” with respect to the stem wall 28 and sidewalls 30 may also include an upright, but slightly sloped orientation, as well, provided it still retains its function and purpose, as described herein. In the embodiment shown, the stem wall 28 is configured substantially as a rectangular block wherein the opposite sidewalls 30 may be substantially parallel to one another.

The forward end of the stem wall 28 may be joined to the rearward face 18 of the wall 14 by a chamfered or thickened area 31 which tapers laterally outward toward the rearward face 18 of the forward wall 14, as is shown in FIG. 1. In other embodiments, no chamfered or thickened area may be provided.

The stem 28 has opposite top and bottom edges 32, 34, respectively, and may have a height measured between the top and bottom edges 32, 34 that is the same or similar to that of the forward wall 14. In other embodiments, the stem wall 28 may have a height that is larger or smaller than that of the forward wall 14. In the embodiment shown, the top and bottom edges 32, 34 are substantially flat and parallel to one another and are substantially flush and level with the top and bottom edges 24, 26 of the forward wall 14.

The rearward edge 36 of the stem wall 28 may be upright and substantially flat and parallel to the forward face 16 of the forward wall 14. The rearward edge 36 or end of the stem 28 may have a variety of other orientations and configurations, as well.

Provided along the top edge 32 of the stem wall 28 of retaining wall unit 10 shown in FIG. 1 are one or more projections or teeth 38. The projections or teeth 38 project upward from the top edge 32 and are longitudinally spaced apart along the length of the stem wall 28. Provided along the bottom edge 34 of the retaining wall unit 10 of FIG. 1 are one or more recesses or notches 40. The recesses or notches 40 are also longitudinally spaced apart along the length of the stem wall 28. The teeth 38 and notches 40 may be longitudinally spaced apart at various distances, such as every 2, 3, 4, 5 feet or more.

As shown in FIG. 2, the teeth and notches 38, 40 of the different retaining wall units 10A, 10B, 10C of the system 12 are configured and arranged to be received within cooperating teeth or notches of the stacked units 10A, 10B, 10C. Thus, the teeth 38 and notches 40 are located at a position along the stem 28 to facilitate the intermeshing of the teeth 38 and notches 40 when the units 10A, 10B, 10C are arranged in the desired stacked configuration. In the system 12 shown, the teeth 38 and notches 40 intermesh when the forward walls 14 of the units 10A, 10B, 10C are all substantially parallel and aligned with one another so that the forward faces 16 all lie in substantially the same plane. In other embodiments, however, the forward walls 14 of the different units 10 may not be aligned or may be offset or staggered from one another, with the teeth 38 and notches 40 being configured to still intermesh with one another. Additionally, as can be seen in FIG. 2, the top edge 32 of the uppermost unit 10A and the bottom edge 34 of the lowermost unit 10C may be substantially flush or free from any teeth 38 or notches 40. In still other embodiments, none or only some of the retaining wall units 10 forming the system may have any teeth 38 and/or notches 40.

Referring to FIG. 3, the configuration of the cooperating teeth 38 and notches 40 can be more readily seen, such as for units 10A, 10B of the system 12 of FIG. 2. The tooth 38 is shown as being in a substantially wedge-shaped configuration with opposite forward and rearward faces 42, 44 that slope inward or towards one another from the base of the tooth 38 and are joined at their upper ends by a substantially flush or level upper face 46. Similarly, the notch 40 has a corresponding wedge shape with opposite forward and rearward faces 48, 50 that slope inward or toward one another towards the recessed ceiling 52 of the notch 40, which is a substantially flat or level face. The dimensions of the tooth 38 are slightly less than those of the notch 40 to provide a sufficient clearance to facilitate positioning of the teeth 38 within the notches 40. The slope of the inward sloping faces 42, 44 and 48, 50 of the tooth 38 and notch 40, respectively, may also be sloped at the same or similar angle to facilitate positioning of the tooth 38 within the notch 40.

FIG. 3 shows non-limiting exemplary dimensions of a cooperating tooth and slot. As shown, the faces 42, 44 of the tooth 38 have an overall height of 4 inches, the upper face has a length of 11 inches and the base has a length of 12 inches. The faces 48, 50 of the notch 40 have a height of 5 inches, the ceiling 52 has a length of 12 inches and the lower opening of the notch 40 has a length of 13 inches. The thickness or width of the tooth 38 and notch 40 may be the same or substantially the same or less than that of the stem 28. Non-limiting exemplary dimensions of the tooth 38 include those having a height of from 2 inches to 12 inches with an overall length of from 6 inches to 3 feet, more particularly from 8 inches to 18 inches. The dimensions of the cooperating notch would be slightly larger such that an overall clearance of from about ¼ to about 1 inch may be provided around the perimeter of the tooth 38 when engaged with the notch 40. The teeth 38 and notches 40 may have other cooperating shapes, configurations and sizes as well.

Although the teeth 38 are shown as being located on the top edge 32 of the stem 28 and the notches 40 are shown provided on the bottom edge 34, they may be located on the opposite edges as well. Thus, the teeth 38 could be located on the bottom edge 34 and the notches 40 could be located on the top edge 32.

Referring to FIGS. 1 and 2, provided on one or both opposite sidewalls 30 of the stem wall 28 are one or more or a series of elongated sloped grooves 54 formed in the surface of the sidewall 30 of the unit 10. The grooves 54 may have a length or longitudinal axis that is sloped upward toward the forward wall 14 at an angle A relative to the longitudinal axis of the stem wall 28. The angle A (FIG. 2) of the grooves 54 relative to the longitudinal axis of the stem wall 28 may range from about 10° to about 75°, more particularly from about 15°, 20°, 25°, 30° or 35° to about 50°, 55°, 60°, 65°, or 70. In certain embodiments, the angle of slope A of the grooves 54 is from about 25° to about 70°. As will be more fully later on, the angle A may be selected based upon the angle of a failure plane of the particulate mass that the retaining wall unit 10 is intended to be use with. The grooves 54 may be longitudinally spaced apart along the length of the stem 28 at various distances that may be the same or different between each groove 54 on each sidewall 30. The distance between each groove 54 may range from about 3 inches or more to about 3 feet or less. In certain embodiments the grooves 54 may be longitudinally spaced apart along each sidewall 30 from about 6 inches to about 18 inches.

Each sloped groove 54 may be formed as a single continuous groove or a series of non-continuous groove sections that are substantially aligned along a single line or axis. If non-continuous, the sections may be longitudinally spaced only a few inches apart, such as less than 12 inches apart. As used herein, the description applied to a single groove may apply to such a groove formed as either a single continuous groove or a series of aligned groove sections, unless it is expressly stated or is otherwise apparent from its context. The length of each sloped groove 54 may extend across substantially the entire height of the stem wall 28. This may be approximately ⅝, ⅔, ¾, ⅞ or more of the stem wall height as defined by the top and bottom edges 32, 34. In some embodiments, the groove 54 may extend across the entire height of the stem wall 28. In other embodiments, one or both ends of the groove 54 may be spaced from the top and bottom edges 32, 34. In certain embodiments, the grooves 54 may extend beyond the top and bottom edges 32, 34 where the grooves 54 intersect the teeth 38. In such cases, the grooves 54 may extend across the entire height or a portion of the height of the teeth 38. In other embodiments, the grooves 54 terminate at the base of the teeth 38 and along the edges of the notches 40. In still other embodiments, the ends of the grooves 54 are spaced apart from the teeth 38 and notches 40.

Referring to FIG. 4, a cross section of the stem wall 28 is shown. As can be seen, the grooves 54 have a substantially wedge shape with opposite converging sidewalls 56, 58 that converge to a point or peak 60. The grooves 54 may have a depth that extends into the sidewall a distance that is less than ½ the thickness of the stem wall 28. In most instances, the depth of the grooves 54 will range from about ½ inch or more, more particularly from about ½ inch to about 4 inches, and still more particularly from about ½ or 1 inch to about 3 inches. The depth of the grooves 54 may also be dependent upon the thickness of the stem wall 28 so that they do not structurally weaken the stem wall 28 significantly. In the embodiment shown, the transverse cross section of the groove 54 is configured as an equilateral or isosceles triangle with the length of the sidewalls being the same. In other embodiments, however, the length of the sidewalls 56, 58 may be different, thus having a transverse cross section configured as a scalene triangle. In some embodiments, the sidewall of longer length may be the rearward sidewall 56 so that the forward sidewall 58 is oriented at a steeper angle relative to the surface of the stem sidewall 30, with the forward sidewall 58 of the groove 54 even being perpendicular or at an acute angle relative to the surface of the stem sidewall 30.

The transverse width of the grooves 54 at the greatest transverse cross dimension may range from about ½ inch or more, more particularly from about ½ inch to about 4 inches, and still more particularly from about ½ or 1 inch to about 3 inches. The width of the grooves 54 may be substantially uniform along the length of the groove or may vary.

The length or axis of the grooves 54 on either sidewall 30A, 30B may oriented at the same angle and be parallel to those on the opposite sidewall 30. As shown in FIG. 4, the grooves 54 on the opposite sidewalls 30A, 30B are arranged in a longitudinally staggered configuration along the length of the stem 28 from those of the opposite stem sidewall 30. Thus, for example, the grooves 54 on sidewall 30A, may be spaced every 12 inches apart at 12 inches, 24 inches, 36 inches, 48 inches, etc. along the length of sidewall 30A. For sidewall 30B, the grooves 54 may be spaced every 12 inches apart at 6 inches, 18 inches, 30 inches, 42 inches, etc. along the length of sidewall 30B. This facilitates preventing the formation of weak spots that might otherwise form if the grooves 54 on either side were aligned. In some embodiments, the grooves 54 may be oriented at different angles and be non-parallel. In such cases, the grooves 54 may still be staggered and may or may not longitudinally overlap or cross along their lengths. In most embodiments, the grooves 54 are oriented at the same angle and are parallel to those of the opposite sidewall 30 and are longitudinally staggered along the length of the stem wall 28.

FIG. 5 shows an alternate embodiment of grooves 62 that may be formed in the sidewalls 30A, 30B. The length, orientation and spacing of the grooves 62 may be the same or similar as those described for the grooves 54. The grooves 62 are also wedge-shaped and have inward sloping sidewalls 64, 66. Instead of converging to a point or peak, however, the sidewalls 64, 66 slope inward to a floor 68, which may be substantially flat and parallel with the face of the sidewall 30. The transverse cross section of the groove 62 may be configured as an isosceles trapezoid when both sidewalls 64, 66 have the same length. In certain embodiments, the sidewalls 64, 66 may be of different lengths and the floor 68 may be non-parallel to the sidewall 30 such that the groove 62 has a transverse cross section that is configured as a scalene or right-angle trapezoid. In some embodiments, the groove sidewall of longer length may be the rearward sidewall 64 so that the forward sidewall 66 is oriented at a steeper angle relative to the surface of the sidewall 30.

Other transverse cross-sectional shapes may be used for the elongated grooves, such as the grooves 54 and 66, formed in the sidewalls 30. These may be polygonal or arcuate shapes (e.g. half-circle) or combinations of these shapes. The cross-sectional shape of the grooves may be limited, however, to the type of form used for forming the grooves in the concrete materials forming the retaining wall units 10. The forms used are typically removed, therefore a wedge-shape or shape that expands outward from the depth of the groove to the sidewall surface is typically used to facilitate their removal.

Each of the individual retaining wall units 10 are formed from a single precast unit of concrete material. The units 10 may incorporate steel reinforcement bars (rebar) imbedded within the forward wall 14 and stem wall 28 to provide strength. Referring to FIGS. 4 and 5, the stem wall 28 is shown with lengths of rebar 70 that are laterally spaced apart along the height of the stem 28 and extend longitudinally along the length of the stem 28. The ends of the rebar 70 extend through the chamfered area 31 and into the forward wall 14, with the rebar 70 being bent at substantially right angles so that the remaining length of the rebar 70 is imbedded in and extends along the width of one side of the forward wall 14. The rebar 70 may be bent in alternate substantially horizontal directions within the forward wall 14 so that some ends of the rebar 70 may extend to the left side edge 20 and some extend toward the right side edge 22. In some embodiments, the ends of the rebar 70 may also be bent in substantially vertically directions so that the ends of the rebar 70 extend toward the top and bottom edges 24, 26 of the forward wall 14. The ends of rebar 70 imbedded within the forward wall 14 may also be bent at substantially right angles but oriented in non-vertical and non-horizontal directions in some embodiments. Additional lengths of rebar (not shown), which may be vertically, horizontally or in other orientations, may also be provided and imbedded in the forward wall 14.

FIG. 6 is a diagram of an example of a suitable rebar configuration useful for the stem 28. As shown, the configuration includes the longitudinal lengths of rebar 70 that extend along the stem wall length. Vertical lengths of rebar 72 that extend across substantially the entire height or a portion of the height of the stem wall 28 are also provided. Within the sections of the stem wall 28 that include teeth 38 and the areas of the stem wall between the notches 40, U-shaped lengths of rebar 74 may be used to reinforce these projecting areas of the stem wall 28. As shown in FIG. 6, the rebar 74 may have a width that facilitates incorporating the U-shaped end of the rebar 74 into the teeth 38. More than one U-shaped length of rebar 74 may be used in wider areas, such as between the notches 40.

Referring to FIG. 7, a retaining wall system 80 is shown, similar to the system 12 of FIG. 2. As shown, the system 80 is composed of a number of retaining wall units similar to the units 10 and 10A-10C previously described, and designated generally at 10. As shown, the units 10 are stacked one on top of the other as eight different unit levels, designated Levels A1-A8. As can be seen, the teeth 38 and notches 40 of the stacked units 10 are intermeshed with one another with the forward face 16 of the forward walls 14 all being substantially parallel and flush with one another when stacked. Furthermore, the grooves 54 of each unit 10 of the different levels of the constructed system 80 may also be substantially parallel to one another.

It can also be seen that the lower units have increasingly longer stem walls 28, with the stem wall 28 of Level A1 having the greatest length. Levels A2 and A3 have the same stem length but are shorter than that of Level A1. Level A4 has a stem length that is shorter than that for Level A3, etc. The top unit 10 at Level A8 has the shortest stem length. As can be seen, each unit 10 may have a different stem length, or two or more of adjacent units may have the same or a similar stem length. The units 10 will be precast in the different sizes necessary for constructing the system 80 or a similar system. As a non-limiting example, the unit of the bottom level (Level A1) may have a stem length of approximately 32 feet. The units of the remaining units may be shorter in increments of from, for example, 2 to 6 feet. Thus, for example, the units of Levels A2 and A3 may be 3 feet shorter with a stem length of 29 feet. The unit 10 of Level A4 may have a stem length of 26 feet, etc., with the unit 10 of uppermost Level A8 having a stem length of only 15 feet. Although FIG. 7 shows only a single stack of units 10, it will be appreciated by those skilled in the art that the system 80 will have several stacks of units 10 positioned laterally side-by-side such that the complete retaining wall system 80 is several units wide and tall.

The retaining wall system 80 is used to retain a backfill mass of soil, earth or other particulate or granular material designated at 82. As can be seen, the surface of the backfill 82 may slope downward to or near the top of the forward wall 14 of the uppermost unit of Level A8. The backfill slope or angle of slope relative to the top of retaining unit 10 of Level A8 is designated β.

FIG. 7 shows the failure plane 84 of the particulate mass 82. The failure plane 84 is understood to be the sloped surface between two layers of particulate material that may tend to mechanically fail, with one layer often sliding off, such as in an avalanche, with respect to the other layer. The failure plane 84 is oriented at an angle α with respect the horizontal plane on which the particulate mass 82 rests. The angle α may be referred to as the failure plane angle. This failure plane 84 angle α will typically be substantially the same for homogeneous particulate or granular materials for the failure plane 84 located along any point along the height of the particulate material 82.

The failure plane angle α is generally related to angle of internal friction φ of the various backfill materials forming the mass 82. In its simplest form, the failure plane angle may be represented by the general Equation (1) below:

α=45°+φ/2  (1)

The angle of internal friction φ varies for the type of particulate material forming the mass 82. Typically, φ will range from about 25° to about 45° for most particulate materials. For loose or random particulate backfill, for example, φ may be range from around 29° to 31. For dense, compact or cohesive backfill materials, φ may range around 32 to 36. For other more dense, compact or cohesive particulate materials, φ may be even higher, with cement fortified backfill having high cohesion often having an angle of internal friction φ of about 45°. It can thus be seen from Equation 1 that a backfill mass 82 with an angle of internal friction φ of 30° will result in failure plane angle α of approximately 60°. Other factors may also influence failure plane angle α and may be readily determined by those skilled in the art.

As can be seen in FIG. 7, the grooves 54 of the units 10 of the system 80 are oriented approximately perpendicular or 90° to the failure plane 84 of the soil mass 82, although other angles that facilitate an increase in frictional interaction between the grooves 54 of the retaining wall stems 28 and the backfill material 82 may also be used. The 90° orientation of the grooves 54 relative to the failure plane 84 maximizes the frictional interaction between the stems 28 and the backfill material 82 and increases the stability of the backfill material 82. This is due, at least in part, to the direct abutment and engagement of forces exerted against the walls of the grooves 54. This may also facilitate decreasing the lateral pressure exerted against the forward walls 14 of the retaining wall units 10 of the system 80.

By providing retaining wall units 10 with different orientations of grooves 54, the retaining wall units 10 may be selected and used with various backfill materials based upon the calculated or estimated failure plane angle α for the particulate material being retained. In some embodiments, the retaining wall units 10 may be provided or used with grooves 54 that are angled to be substantially perpendicular to the failure plane angle α of the looser backfill material, such as those having an internal angle of friction φ of from 25° to 31° so that α is from 57.5° to 60.5° according to Equation 1. Thus, for back fill material having a failure plane angle α of approximately 60°, the angle A of the grooves, as shown in FIG. 2, would be approximately 30° such that the grooves would be oriented generally perpendicular to the 60° failure plane. Retaining wall units with grooves oriented so that they are perpendicular to the failure planes of such loose materials would still be well suited with those particulate materials having higher internal angles of friction since such materials area less prone to failure. This is true even though the grooves of such retaining wall stems 28 are not necessarily oriented perpendicular to the failure plane of the materials having larger internal angles of friction (I).

FIG. 8 shows the front face of a retaining wall system 90, which may similar to those previously described, with stacks of retaining wall units 10 arranged in side-by-side configuration, with the retaining units 10 of each stack being in vertical alignment as well. As shown in FIG. 8, not all of the retaining wall units of each vertical stack or column have the same height. This may allow the height of the retaining wall system 90 to be selectively varied across its width, as may be necessary or desired. The retaining units 10 in each vertical column each have substantially the same width so that the side edges 20, 22 of the forward walls 14 are substantially aligned and are not in a staggered or overlapping configuration. This facilitates downward drainage of water or other liquids through the small gaps and spaces between the individual wall units 10. As can be seen in FIG. 8, in this embodiment the tops of the uppermost retaining wall units 10 are arranged in a stepped configuration so that they are not level or flush. A layer or layers of poured concrete, mortar or other fill material 92, which may be poured into a suitable temporary form or mold, may be used to provide a substantially flush upper surface for the forward walls 14 of the uppermost units 10.

One or more cap units 94 may be positioned over the upper ends of the forward walls 14 of the upper most units 10 and over any layer or layers of concrete or fill material 92. FIG. 9 shows a more detailed view of a cap unit 94. The cap unit 94 may be formed from reinforced or non-reinforced concrete and be precast. The cap unit 94 has spaced apart forward and rearward walls 96, 98, respectively, that each extend downward from a head member 100, which may be a substantially planar member. The cap unit 94 has a substantially U-shaped transverse cross section to define a longitudinal wall channel or recess 102 for receiving the top portion of the forward walls 14 of the retaining wall units 10.

A slot 104 is shown formed in the rearward wall 98 that communicates with the channel 102. Additionally, cutouts 106, 108 are shown formed in the rearward wall 98 at either end of the cap unit 94 that also communicate with the channel 102 and extend from the lower edge of the rear wall 98 to the head member 100. The slot 104 and cutouts 106, 108 are sized and configured for receiving and accommodating the forward portion of the stem 28, such as the chamfered area 31, that joins the forward wall 14. As used herein, the term “cutout” or similar expressions is not necessarily meant to be construed as an area that has actually been cut, although it may be in certain embodiments, but merely refers to its appearance. The cutouts 106, 108 may have a width that is less than that of the slot 104, as the cutouts 106, 108 may only accommodate half of the width of the stem 28, with the other half being received by the cutout of an adjacent cap unit.

The cap units 94 are shown as being sized to be twice the width as each of the walls 14, so that each cap unit 94 is centered over and covers a single wall 14 of a retaining unit 10, with the ends of the cap unit 94 covering approximately half of the adjacent walls 14 of the adjacent retaining wall units 10. The cap units 94 may be sized differently to cover only a single wall unit 10 or only portions of a wall unit 10. Cap units 94 may also be differently sized to accommodate the ends of the retaining wall system or other non-uniform areas.

FIG. 10 shows a retaining wall system 110 composed of retaining wall units 10, such as those previously described. In this embodiment, the retaining wall units 10 are laterally spaced apart. The distance may vary, but in the embodiment shown the retaining wall units 10 are spaced apart a distance approximate to the width of a forward wall 14 of one of the units 10. A face wall unit 112 is provided for closing the gap between the adjacent spaced apart units 10. The face wall unit 112 is sized and configured for engaging opposite sides of the forward wall 14 of the laterally spaced apart retaining wall units 10. As shown, the face wall unit 112 is a substantially flat planar member, which may be formed from reinforced or non-reinforced concrete, that has vertically extending cutout areas 114 that define a flange or extended area 116 on either side of the unit 112 that abuts against the rearward face 18 of each of the forward walls 14 along the left and right edges 20, 22. As shown, the face wall unit 112 is substantially upright when so engaged with the wall units 10. The cutout areas 114 may be sized and configured so that when the face wall unit 112 is so engaged, the forward face 118 of the unit 112 may be substantially flush with the forward face 16 of the units 10.

FIG. 11 shows a front view of the face wall unit 112. As can be seen, a series of weep holes 115 are provided that extend through the thickness of either flange 116 adjacent to the corner formed by the cutout area 114. The holes 115 may be located at a position so that they are proximate to or just to the outside of the side edges 20, 22 of the forward walls 14 of the units 10. The week holes 115 facilitate drainage of water or liquids from behind the wall units 112 and are positioned so that such water or liquids may drain through the space or gap between the side edges of the forward wall and cutout areas 114. The holes 115 may have a diameter or transverse cross dimension of from about ½ to about 1½ inches. The holes 115 may be spaced from about 3 to about 12 inches apart along the height of the wall unit 112, more typically from about 6 to about 10 inches, although this distance may vary.

FIG. 12 shows a top view of an alternate embodiment of a face wall unit 112 having a rearward face 117 that has one or more recessed portions 119. This reduces the thickness of the face wall unit 112 and thus its weight, while still maintaining sufficient strength for the face wall unit 112.

FIGS. 13A and 13B show another retaining wall system 120 that may employed at a corner area of a backfill mass. FIG. 13A shows a lower level corner assembly 122A of the system 120 that is formed by different retaining wall units designated generally at 10 and which may be the same or similar to those previously described. As shown in FIG. 13A, the retaining wall units 10D along the left side of the corner assembly 122A have stems 28 that extend rearward a significant distance. The retaining wall units 10E located along the bottom of the corner assembly 122A are substantially perpendicular to the units 10D, as shown, although the units 10D, 10E may be oriented at other non-straight and non-perpendicular angles to one another. The retaining wall units 10E, however, have stems 28 that are shorter than those of the units 10D so that they project toward but do not contact the stem 28 of the closest adjacent unit 10D. The retaining wall units 10F and 10G and/or the stems 28 thereof of both the left and bottom side, respectively, of the corner assembly 122A are located at a position longitudinally rearward from the stems 28 of the units 10E or 10D, respectively, so that they do not intersect or interfere with the stems of either of the units 10E or 10D.

As shown in FIG. 13A, the edges of the units 10D and 10E located at the corners of the corner assembly 122A are spaced apart to define a corner gap. A corner face wall unit 124 configured for engaging opposite sides of the forward walls of the most adjacent wall units of the wall units 10D and 10E. As shown, the face wall unit 124 is configured as an angular body having angular configuration that corresponds to the angle of the forward wall 14 of the retaining wall units 10D, 10E. The corner face wall unit 124 may otherwise be configured similarly to the face wall unit 112, previously described, including the weep holes 115 and recessed portion(s) 119, and may be formed from reinforced or non-reinforced concrete and have vertically extending cutout areas 126 that define a flange or extended area 128 on either side of the unit 124 that abuts against the rearward face 18 of each of the forward walls 14 along the left and right edges 20, 22 of the units 10D, 10E. The cutout areas 126 may be sized and configured so that when the face wall unit 112 is engaged with the wall units 10D, 10E, the forward faces 130 of the unit 124 may be substantially flush with the forward face 16 of the unit 10D or 10E with which it is engaged. The face wall unit 124 may have a curved or non-angular configuration as well, with the forward face 130 being an arcuate face.

FIG. 13B shows a corner assembly 122B of the system 120 that is configured to be stacked upon the corner assembly 122A of FIG. 13A. The corner assembly 122B is similar to the corner assembly 122A and includes similar retaining wall units 10D, 10E, 10F and 10G to those of the lower level corner assembly 122A, except that they arranged differently. In assembly, the retaining wall units 10D of the corner assembly 122B are positioned above the units 10E for the corner assembly 122A. Likewise, the retaining wall units 10E are positioned above the retaining wall units 10D of the lower level corner assembly 122A. The retaining wall units 10F of each assembly 122A, 122B are positioned one on top of one another and the retaining wall units 10G are positioned one on top of one another, as well, with the notches 40 and teeth of the respective stacked units engaging one another. Notches 40 formed in the in the stem 28 of the units 10E and in the forward portion of the stem 28 of the retaining wall units 10D of the assembly 122B will receive the teeth 38 of the underlying retaining wall units 10D and 10E, respectively, of the assembly 122A. The rearward portions of the stems 28 of the units 10D of the assembly 122B will cross and rest on the rearward portions of the stems 28 of the units 10D of the assembly 122A. Notches 40 and teeth 38 of these rearward portions of the overlapping units 10D may be spaced or configured so that they do not interfere with one another or are otherwise accommodated. In certain embodiments, the teeth 38 and notches 40 may be eliminated entirely from one or all of the units 10 of the corner assembly system 120. A corner face unit 124 is also utilized for the corner assembly 122B, just as with 122A.

Additional levels of corner assemblies may be added, as is desired or necessary, to the corner assemblies 122A, 122B, with some of the stems overlaying and crossing those of the underlying level or assembly. The length of the stems 28 of the upper level corner assemblies may be progressively shortened, as with the retaining wall systems previously described. By alternating the lengths and orientation of the stems 28 of each level, as shown and described, a structurally stable corner retaining wall system may be constructed.

For any of the retaining wall systems shown and described, the various units and components are typically positioned and retained in place due to their weight and their integration into and with the particulate backfill material with which they are used. Thus, it is typically not necessary to utilize mortar or other joining materials for joining the individual components together. In certain cases, however, such mortar or other materials may be used for functional and/or aesthetic purposes, if desired.

While the invention has been shown in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes and modifications without departing from the scope of the invention. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention. 

1. A retaining wall system for use in retaining a backfill particulate mass comprising: at least one retaining wall unit comprising: a substantially upright forward wall having a rear surface for abutting against the backfill particulate mass; and a substantially upright stem wall that extends rearward from the rear surface of the forward wall, the stem wall having opposite substantially upright sidewalls, and wherein at least one of the sidewalls has a series of longitudinally spaced apart elongated grooves that slope upward toward the forward wall.
 2. The retaining wall system of claim 1, wherein: both sidewalls of the stem wall having a series of longitudinally spaced apart elongated grooves that slope upward toward the forward wall.
 3. The retaining wall system of claim 1, wherein: the series of longitudinally spaced apart elongated grooves of each sidewall are arranged in a longitudinally staggered configuration from those of the opposite sidewall.
 4. The retaining wall system of claim 1, wherein: the elongated grooves each have a wedge-shaped transverse cross section.
 5. The retaining wall system of claim 1, wherein: the elongated grooves each have a depth of from about ½ inch or more.
 6. The retaining wall system of claim 1, wherein: the elongated grooves each have a depth of from about ½ inch to about 4 inches.
 7. The retaining wall system of claim 5, wherein: the elongated grooves each have a transverse width of from about ½ inch or more.
 8. The retaining wall system of claim 5, wherein: the elongated grooves each have a transverse width of from about ½ inch to about 4 inches.
 9. The retaining wall system of claim 1, further comprising: a second retaining wall unit comprising a substantially upright forward wall and a substantially upright stem wall that extends rearward from the rear surface of the forward wall; the first and second retaining wall units being provided with at least one of a cooperating projection and recess provided with one of the upper and lower ends of the stem walls of the first and second retaining wall units, the cooperating projection and recess being configured so that the projection of one of the first and second retaining wall units is received in the recess of the other when the first and second retaining wall units is stacked one on top of the other.
 10. The retaining wall system of claim 9, wherein: the stem wall of the second retaining wall unit also has opposite substantially upright sidewalls, and wherein at least one of the sidewalls of the second retaining wall units is also provided with a series of longitudinally spaced apart elongated grooves that slope downwardly rearward.
 11. The retaining wall system of claim 1, wherein: the lengths of the elongated grooves are oriented at an angle of from about 10° to about 75° relative to a longitudinal axis of the stem wall.
 12. The retaining wall system of claim 1, wherein: the lengths of the elongated grooves are oriented at an angle from about 15° to about 70° relative to a longitudinal axis of the stem wall.
 13. The retaining wall system of claim 1, further comprising: a second retaining wall unit comprising a substantially upright forward wall and a substantially upright stem wall that extends rearward from the rear surface of the forward wall; and an upright face wall unit configured for engaging opposite sides of the forward wall of the first and second retaining wall units when the first and second retaining wall units are laterally spaced apart to provide a gap therebetween with the face wall unit being positioned between the first and second retaining wall units to close the gap.
 14. The retaining wall system of claim 1, further comprising: a second retaining wall unit comprising a substantially upright forward wall and a substantially upright stem wall that extends rearward from the rear surface of the forward wall; and a cap unit having a longitudinal wall channel for receiving the upper ends of the forward walls of the first and second retaining wall units when the first and second retaining wall units are arranged in a substantially side-by-side configuration, the cap unit having at least one of a stem wall slot and cutout that communicates with the longitudinal channel for receiving at least one of the stem walls of the first and second retaining wall units.
 15. The retaining wall system of claim 1, further comprising: a second retaining wall unit comprising a substantially upright forward wall and a substantially upright stem wall that extends rearward from the rear surface of the forward wall, the second retaining wall being configure for cooperating engagement with the first retaining wall unit when the forward walls of the first and second retaining wall units are oriented substantially perpendicular to one another other; and a corner face wall unit configured for engaging opposite sides of the forward walls of the first and second retaining wall units when the first and second retaining wall units are in proximity to one another and oriented at a non-straight angle to one another to form a corner gap with the corner face wall unit being positioned between the first and second retaining wall units to close the corner gap.
 16. A retaining wall system for use in retaining a backfill particulate mass comprising: at least two retaining wall units, each retaining wall unit comprising: a substantially upright forward wall having a rear surface for abutting against the backfill particulate mass; and a substantially upright stem wall that extends rearward from the rear surface of the forward wall, the stem wall having opposite substantially upright sidewalls, and wherein at least one of the sidewalls has a series of longitudinally spaced apart elongated grooves that slope upward toward the forward wall, the lengths of the elongated grooves being oriented at an angle from about 10° to about 75° relative to a longitudinal axis of the stem wall; the retaining wall units each being provided with at least one of a cooperating projection and recess provided with one of the upper and lower ends of the stem walls of the retaining wall units, the cooperating projection and recess being configured so that the projection of one of the retaining wall units is received in the recess of the other when the first and second retaining wall units are arranged in stacked configuration one on top of the other.
 17. The retaining wall system of claim 16, wherein: both sidewalls of the stem wall of each retaining wall unit has a series of longitudinally spaced apart elongated grooves that slope upward toward the forward wall.
 18. The retaining wall system of claim 16, wherein: the series of longitudinally spaced apart elongated grooves of each sidewall of each retaining wall unit are arranged in a longitudinally staggered configuration from those of the opposite sidewall of each retaining wall unit.
 19. The retaining wall system of claim 16, wherein: the elongated grooves each have a depth of from about ½ inch or more and a transverse width of from about ½ inch or more.
 20. The retaining wall system of claim 16, wherein: the lengths of the elongated grooves are oriented at an angle from about 15° to about 70° relative to a longitudinal axis of the stem wall of each retaining wall unit.
 21. The retaining wall system of claim 16, wherein: the elongated grooves each have a depth of from about ½ inch to about 4 inches and a transverse width of from about ½ inch to about 4 inches. 